Physical Sciences Grade 12 Paper 2 Mpumalanga Mock 2022 Memo

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Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com NATIONAL SENIOR CERTIFICATE GRADE 12 PHYSICAL SCIENCES: CHEMISTRY P2 SEPTEMBER 2022 MARKING GUIDELINES MARKS/PUNTE: 150 This memorandum consists of 14 pages. Hierdie memorandum bestaan uit 14 bladsye.

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 2 September 2022 NSC/NSS- Marking Guidelines QUESTION 1 / VRAAG 1 1.1 C ✓✓ 1.2 D ✓✓ 1.3 A ✓✓ 1.4 B ✓✓ 1.5 D ✓✓ 1.6 B ✓✓ 1.7 D ✓✓ 1.8 C ✓✓ 1.9 B ✓✓ 1.10 A ✓✓ [20] QUESTION 2 / VRAAG 2 2.1 A bond or an atom or a group of atoms that determine(s) the physical and chemical properties of a group of organic compounds.✓✓ (2 or 0) ‘n Binding of 'n atoom of 'n groep atome wat die fisiese en chemiese eienskappe van 'n groep organiese verbindings bepaal. ✓✓ (2 or 0) (2) 2.2.1 H O H  H C C C H H H (1) 2.2.2 F  (1) 2.2.3 5-bromo-2-chloro-2-methylhexane 5-bromo-2-chloro-2-methylhexane Marking criteria/Nasienriglyne: • Correct stem i.e. hexane./Korrekte stam d.i. heksaan.  • All substituents (bromo, chloro and methyl) correctly identified./Alle substituente (bromo, chloro en metiel) korrek geïdentifiseer.  • IUPAC name completely correct including numbering, sequence, hyphens and commas./IUPAC-naam heeltemal korrek insluitende volgorde, koppeltekens en kommas .  (3) Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 3 September 2022 NSC/NSS- Marking Guidelines 2.2.4 Propanone / Propanoon  (1) 2.2.5 Ketones/Ketone  (1) 2.2.6 H Marking criteria / Nasienriglyne • Only functional group correct / Slegs H C H funksionele groep korrek  • Two methyl groups / Twee metielgroepe H H H H ✓ • Whole structure correct / Hele struktuur H C C C C C H korrek  H O H H H H C H H (3) 2.2.7 Secondary/Sekondêr (1) 2.3.1 Unsaturated/Onversadig ✓ It is a compound with one or more multiple bonds between C atoms in their hydrocarbon chains. ✓ Verbindings waarin een of meer meervoudige bindings tussen C-atome in hul koolwaterstofkettings voorkom. (2) 2.3.2 Bromine water / Br2 (Accept KMnO4)  Broom water / Br2 (Aanvaar KMnO4) (1) 2.3.3 CnH2n+2 (1) [17] Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 4 September 2022 NSC/NSS- Marking Guidelines QUESTION 3 / VRAAG 3 3.1 Propane / Propaan ✓ (1) 3.2.1 Organic molecules with the same molecular formula, ✓ but different structural formulae.✓ Organiese molekule met dieselfde molekulêre formule, maar verskillende struktuurformules. (2) 3.2.2 Chain isomer / Kettingisomeer✓ (1) 3.2.3 • Structure: Compound B has a larger surface area than compound C. ✓ • Intermolecular forces: The intermolecular forces in B is stronger than in C. ✓ • Energy More energy required to overcome/break intermolecular forces in B than in C . ✓ • Struktuur: Verbinding B het ‘n groter kontak oppervlak as verbinding C. • Intermolekulêre kragte: Intermolekulêre kragte in verbinding B is sterker as in verbinding C. • Energie: Meer energie benodig om intermolekulêre kragte te oorkom/breek in B as in C. OR • Structure: Compound C is more compact or spherical as B, the surface area is smaller.✓ • Intermolecular forces: The intermolecular forces in C is weaker than in B.✓ • Energy Less energy needed to overcome/break intermolecular forces in C. ✓ • Struktuur: Verbinding C is meer kompak of series as B, die kontak oppervlak is Kleiner • Intermolekulêre kragte: Die intermolekulêre kragte in C is swakker as in B • Energie Minder energie benodig om intermolekulêre kragte te oorkom/breek in C Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 5 September 2022 NSC/NSS- Marking Guidelines 3.3.1 Marking criteria/Nasienriglyne If any one of the underlined key phrases in the correct context is omitted, deduct 1 mark./Indien enige van die onderstreepte frases in die korrekte konteks uitgelaat is, trek 1 punt af, The pressure exerted by a vapour at equilibrium with its liquid in a closed system. Die druk uitgeoefen deur 'n damp in ewewig met sy vloeistof in 'n geslote sisteem. (1) 3.3.2 D (1) 3.3.3 • Both compounds/D and E have (in addition to London forces and dipole- dipole forces) hydrogen bonding.  Beide verbindings/D en E het waterstofbindings (behalwe Londonkragte en dipool-dipoolkragte). • Compound D/pentan-1-ol/alcohol has one site for hydrogen bonding and compound E/butanoic acid/carboxylic acid has two/more sites for hydrogen bonding. OR D/butanoic acid/carboxylic acid has two/more sites for hydrogen bonding. Verbinding D/pentan-1-ol/alkohol het een punt vir waterstofbindings en verbinding B/buurutanoës/karboksielsuur het twee/meer punte vir waterstofbindings OF B/butanoësuur/karboksielsuur het twee/meer punte waterstofbindings. • Intermolecular forces in compound E/butanoic acid/carboxylic acid are stronger than intermolecular forces in compound D/ butan-1-ol/alcohol. Intermolekulêre kragte in verbinding E/butanoësuur/karboksielsuur is sterker as die intermolekulêre kragte in verbinding D/ pentan-1-ol/alkohol. OR/OF Intermolecular forces in compound D/pentan-1-ol/alcohol are weaker than intermolecular forces in compound E/butanoic acid/carboxylic acid. Intermolekulêre kragte in verbinding E/pentan-1-ol/alkohol is swakker as intermolekulêre kragte in verbinding D/butanoësuur/karboksielsuur. • More energy is needed to overcome/break intermolecular forces in compound E/butanoic acid/carboxylic acid than in compound D/ pentan-1-ol/alcohol.  Meer energie word benodig om intermolekulêre kragte in verbinding E/butanoësuur as in verbinding D/ pentan-1-ol/alkohol te oorkom/breek. OR/OF Less energy is needed to overcome/break intermolecular forces in compound D/pentan-1-ol/alcohol than in compound E/butanoic acid/carboxylic acid. Minder energie word benodig om intermolekulêre kragte in verbinding D/ pentan-1-ol/alkohol te oorkom/breek as in verbinding E/butanoësuur/karboksielsuur. (4) [14] Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 6 September 2022 NSC/NSS- Marking Guidelines QUESTION 4/ VRAAG 4 4.1.1 I: Addition/ hydrohalogenation/hydrobromination Addisie/Hidrohalogenering/Hidrobrominasie II: Elimination/Dehydrohalogenation Eliminasie/Dehidrohalogenering III: Addition/Hydration Addisie/Hidrasie/Hidratering IV: Elimination/Cracking Eliminasie / Kraking (4) 4.1.2 2-bromopentaan / 2-bromopentaan  (2) 4.1.3 Alkene / Alkeen  (1) 4.1.4 H2O/water  (1) 4.1.5 H✓ Marking criteria / Nasienriglyne • Only functional group correct / Slegs H O H H H ✓ funksionele groep korrek  H C C C C C H • Whole structure correct / Hele struktuur H H H H H korrek  (2) 4.1.6 C2H6  Ethane/Etaan✓ (2) 4.2.1 Methyl ethanoate / Metieletanoaat (2) 4.2.2 A dehydrating agent/catalyst ✓ Dehidreermiddel/katalisator (1) 4.2.3 Marking criteria: • Substitute 74 g·mol-1 into the correct formula  • Use ratio: n(CH4O) = n(C3H6O2)  • Substitute 32 g·mol-1 into the correct formula  • 60% of mass of CH4O  • Final answer: 49,64 g  Nasienkriteria: • Vervang 74 g·mol-1 in korrekte formule  • Gebruik verhouding: n(CH4O) = n(C3H6O2)  • Vervang 32 g·mol-1 in korrekte formule  • 60% of mass of CH4O • Finale antwoord: 49,64 g  Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 7 September 2022 NSC/NSS- Marking Guidelines m n= M 68,88 = 74✓ = 0,9308 mol n(CH4 O) = n(C3 H6 O2 )✓ = 0,09308 mol m(CH4 O)pure/suiwer = nM = (0,09308)(32) =29,79 g (29,79)(100) Impure(CH4 O) =  60 = 49,69 g  (5) [20] QUESTION 5/ VRAAG 5 5.1 NOTE/LET WEL Give the mark for per unit time only if in context of reaction rate. Gee die punt vir per eenheidtyd slegs indien in konteks met reaksietempo. ANY ONE/ENIGE EEN • Change in concentration  of products/reactants per (unit) time.  Verandering in konsentrasie van produkte/reaktanse per (eenheid) tyd. • Change in amount/number of moles/volume/mass of products or reactants per (unit) time. Verandering in hoeveelheid/getal mol/volume/massa van produkte of reaktanse per (eenheid) tyd. • Amount/number of moles/volume/mass of products formed/reactants used per (unit) time. • Hoeveelheid/getal mol/volume/massa van produkte gevorm/reaktanse gebruik per (eenheid) tyd. • Rate of change in concentration/amount/number of moles/volume/mass. Tempo van verandering in konsentrasie/ hoeveelheid/getal mol/ volume/massa. ✓✓ (2 or/of 0) (2) 5.2 Volume ACCEPT: Rate of reaction/Tempo van reaksie  (1) 5.3.1 (Decreasing gradient indicates) rate of reaction is decreasing. ✓ (Afnemende gradiënt dui aan dat) reaksietempo afneem. (1) Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 8 September 2022 NSC/NSS- Marking Guidelines 5.3.2 (Gradient is zero, indicates) reaction rate is zero ✓ (Gradiënt is nul, wat aandui dat) reaksietempo nul is. (1) 5.4 ∆V Ave rate /Gem. tempo = ∆t ∆V 10 =  20 − 0 V(O2 )produced/berei = 200 cm3 V n(O2 )produced/berei = Vm 200 = 24000 = 0,0083 mol n(H2 O2 ) = 2n(O2 )✓ = (2)(0,0083) = 0,017 mol n c(H2 O2 )used/gebruik = V 0,017 = 0,04 = 0,42 mol∙dm-3  (5) 5.5 Marking criteria / Nasienkriteria: • Graph of Experiment 2 is steeper than gradient of Experiment 2/ Grafiek van Eksperiment 2 het ‘n styler gradient as Eksperiment 2✓ Both graphs ends at the same place/ Beide grafieke eindig op dieselfde plek ✓ Experiment 1 Volume of O2 (cm3) Experiment 2 10 20 30 Time (minutes) (2) Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 9 September 2022 NSC/NSS- Marking Guidelines 5.6.1 Catalyst  OR Increases reaction rate Katalisator OF Toename in reaksie-tempo (1) 5.6.2 • Catalyst lowers activation energy/provides an alternative path of lower activation energy  Katalisator verlaag die aktiveringsenergie/ bied ŉ alternatiewe pad van laer aktiveringsenergie • More particles have sufficient EK OR more particles have EK  EA  Meer deeltjies het genoegsame EK OF meer deeltjie het EK  EA • More effective collisions per unit time/Frequency of effective collisions increase Meer effektiewe botsings per eenheidstyd/ Frekwensie van die effektiewe botsings neem toe (3) [16] QUESTION 6 / VRAAG 6 6.1 ++Marking criteria: +* • Calculate number of moles of H2 and Cℓ2  • Use mole ratio 1:1:2  • Moles at equilibrium • Divide equilibrium moles by Volume (0,5)  • Correct Kc expression (formulae in square brackets)  • Substitute 64 as Kc value  • Substitution of equilibrium concentrations into Kc expression.  • Substitute moles of Cℓ2 and in correct formula. • Final answer: 71 g  Nasienkriteria: • Bereken die aantal mol van H2 en Cℓ2  • Gebruik verhouding 1:1:2  • Mol by ewewig  • Deel mol by ewewig met volume (0,5) ✓ • Korrekte Kc - uitdrukking (formules in vierkanthakies)  • Vervang 64 as Kc-waarde  • Vervanging van ewewigskonsentrasies in Kc -uitdrukking.  • Vervang mol van Cℓ2 en 71 g·mol-1 in korrekte formule  • Finale antwoord: 71 g Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 10 September 2022 NSC/NSS- Marking Guidelines m m n= n= M M 10 355 = = 2 71 = 5 mol H2 = 5 mol Cl2 H2(g) Cℓ2 (g) HCℓ(g) Initial quantity (mol) ✓ 5 5 0 Aanvangshoeveelheid (mol) Change (mol) Verandering (mol) x x 2x Ratio  2x ✓ Quantity at equilibrium (mol)/ 5–x 5–x Hoeveelheid by ewewig (mol) Equilibrium concentration (mol∙dm-3) 5−x 5−x 2x Ewewigskonsentrasie (mol∙dm-3) 0,5 0,5 0,5 [HCl]2 Kc = ✓ No Kc expression, correct substitution/Geen Kc- [H2 ][Cl2 ] uitdrukking, korrekte substitusie: Max./Maks. 8/9 2x 2 ( ) 0,5 64 = ✓ Wrong Kc expres[sion/Verkeerde Kc uitdrukking: 5−x 5−x ( )( ) Max./Maks. 6/9 0,5 0,5 x=4 n(Cl2 )equilibrium/ewewig = 5 − 4 = 1 mCl2 = nM = (1)(71) = 71 g  (9) 6.2 Negative/Negatief  • Decrease in temperature favours the exothermic reaction.  Afname in temperatuur bevoordeel die eksotermiese reaksie. • The forward reaction is favoured. Die voorwaartse reaksie word bevoordeel. • Reaction is endothermic.  Die reaksie is eksotermies. (4) 6.3.1 Remains the same/Bly dieselfde  (1) 6.3.2 Remains the same/Bly dieselfde  (1) [15] Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 11 September 2022 NSC/NSS- Marking Guidelines QUESTION 7 / VRAAG 7 7.1.1 Dilute acids contain a small amount (number of moles) of acid in proportion to the volume of water.  (2 or 0) Verdunde sure bevat 'n klein hoeveelheid (getal mol) suur in verhouding met die volume water. (2) 7.1.2 Strong acids ionise completely in water to form a high concentration of H3O+ ions.  Sterk sure ioniseer volledig in water om 'n hoë konsentrasie H3O+ -ione te vorm. (2) 7.1.3 HSO− 4  (1) 7.1.4 [H3 O+ ] = 2[H2 SO4 ] = 2(0,2) = 0,4 mol∙dm−3 + pH = −log[H3 O ]✓ = −log[0,4] = 0,398 (3) 7.2.1 Basic/Alkalies  (1) 7.2.2 CO2− − − 3 + H2O → OH + HCO3  Balancing  Marking criteria / Nasienkriteria: • Reactants  Products  Balancing  Reaktanse Produkte Balansering • Ignore phases / Ignoreer fases. (3) 7.3 Marking criteria: n c V n • Use of formula c = V or caVa = na  b b b • Substitute 0,1 mol∙dm-3 and 0,0248 dm3 in correct formula • Use ratio: n(NaOH) = 2n(Na2CO3)  • Substitute 0,5 dm3 in correct formula  m • Use 286 g·mol-1 in n = M  • Final answer: 7,09 g  Nasienkriteria: n 𝐶𝑎𝑉𝑎 𝑛𝑎 • Gebruik van formule c = v or 𝐶𝑏𝑉𝑏 = 𝑛𝑏  • Vervang 0,1 mol∙dm-3 en 0,0248 dm3 in korrekte formule • Gebruik ratio: n(NaOH) = 2n(Na2CO3)  • Vervang 0,5 dm3 in korrekte formule  m • Gebruik 286 g·mol-1 in n = M  • Finale1/OPSIE OPTION 1 7,09 g  antwoord: Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 12 September 2022 NSC/NSS- Marking Guidelines n(HCl) = cV✓ = (0,1)(0,0248)✓ = 2,48 × 10−3 mol n(Na2 CO3 ) = 2n(HCl) n(Na2 CO3 ) = 1,24 × 10−3 mol ✓ 1,24 × 10−3 mol (Na2 CO3 ) in 0,025 dm3 ∴ in 0,5 dm3 n(Na2 CO3 ) = 0,0248 mol  m n= M m 0,0248 = 286 m(Na2 CO3) = 7,09 g  OPTION 2 / OPSIE 2 ca Va na = ✓ cb Vb nb (0,1)(24,8)✓ 2 = ✓ (cb )(25) 1 ca = 0,0496 mol∙dm3 n(Na2 CO3 ) = cV n = (0,0496)(0,5) = 0,0248 mol m n= M m 0,0248 = 286 m(Na2 CO3) = 7,09 g  (6) [18] Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 13 September 2022 NSC/NSS- Marking Guidelines QUESTION 8 / VRAAG 8 8.1 Concentration/Konsentrasie: 1 mol·dm-3  Temperature/Temperatuur: 25 °C  (2) 8.2 • To ensure electrical neutrality / Verseker elektriese neutraliteit  • To separate the two electrolytes/Om die elektroliete te skei  (2) 8.3 Ni to Ag  (1) 8.4 Ni(s) + 2Ag+(aq) → Ni2+(aq) + 2Ag(s)  balancing  Marking criteria / Nasienkriteria: • Reactants  Products  Balancing  Reaktanse Produkte Balansering • Ignore double arrows/Ignoreer dubbel pyltjie • Ignore phases / Ignoreer fases. (3) 8.5 n(anode) = ½n(cathode) n(anode) = ½(0,4) = 0,2 mol m n= M m 0,2 = 59 mdecrease/afname = 11,8 g (3) 8.6 B Mg is a stronger reducing agent than Ni. Mg will be oxidized to Mg2+ Mg is ‘n sterker reduseermiddel as Ni en Mg sal dus geoksideer word tot Mg 2+ (4) [15] Copyright Reserved Please turn over

Downloaded from hlayiso.com Downloaded f rom St anmorephysics. com Physical Sciences P2/Fisiese Wetenskappe V2 14 September 2022 NSC/NSS- Marking Guidelines QUESTION 9 / VRAAG 9 9.1 ANY ONE/ENIGE EEN • The chemical process in which electrical energy is converted to chemical energy.  • The use of electrical energy to produce a chemical change • The process during which an electric current passes through a solution/ionic liquid/molten ionic compound. • Decomposition of an ionic compound by means of electrical energy. • Die chemiese proses waarin elektriese energie gebruik word om 'n chemiese verandering te weeg te bring.  • Die chemiese proses waarin elektriese energie omgeskakel word na chemiese energie • Die proses waardeur ‘n elektriese stroom deur ‘n opplossing/ioniese vloeistof/gesmelte ioniese verbinding beweeg. • Ontbinding van ‘n ioniese verbinding met behulp van elektriese energie. (2) 9.2 A (1) 9.3 B (1) 9.4 Cu2+ + 2e- Cu  Marking criteria/Nasienriglyne Cu  Cu2+ + 2e- ( 3⁄3 ) Cu2+ + 2e- ⇌ Cu ( 1⁄3 ) Cu ⇌ Cu2+ + 2e- ( 0⁄3 ) Cu2+ + 2e-  Cu ( 0⁄3 ) (3) 9.5 True/Waar  Rate of oxidation is equal to the rate of reduction Tempo van oksidasie is gelyk aan die tempo van reduksie (2) 9.6 Carbon is unreactive and can conduct electricity  Koolstof is onreaktief en kan elektrisiteit gelei. (2) 9.7 A 2Cℓ- → Cℓ2 + 2e-  Marking criteria/Nasienriglyne Cℓ2 + 2e-  2Cℓ- ( 2⁄2 ) 2Cℓ-  Cℓ2 + 2e- ( 1⁄2 ) Cℓ2 + 2e- ⇌ 2Cℓ- ( 0⁄2 ) 2Cℓ-  Cℓ2 + 2e- ( 0⁄2 ) (3) 9.8 Decrease/Afneem  (1) [15] TOTAL: 150 Copyright Reserved Please turn over